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Mini-ITX Seaberry Adds 11 PCIe Slots to a Raspberry Pi
- h2odragon 5y agoWe're like one or two hardware generations away from having a VME backplane like environment where we'll be able to do some truly nifty and nasty things, at home and hobby levels. The politics of getting a standard out that isn't owned by (and therefore twisted to favor) a couple of big companies is challenging, but it's happened before, right? (crickets)
- tjoff 5y agoVME?
- h2odragon 5y agohttps://en.wikipedia.org/wiki/VMEbus https://en.wikipedia.org/wiki/VMEbus see also https://en.wikipedia.org/wiki/Sun-4 https://en.wikipedia.org/wiki/Sun-4
- myself248 5y agohttps://en.wikipedia.org/wiki/VMEbus https://en.wikipedia.org/wiki/VMEbus Imagine something like ISA but 32 bits wide, with a GPIB-like arbitration scheme. On a backplane that you plug CPU cards and peripheral cards into.
- dragontamer 5y agoI'm pretty sure PCIe is that today. PCIe CPUs may have failed commercially, but they prove that its possible (Xeon Phi). PCIe GPUs are common. 4x or 8x GPUs are your typical mining rigs. Perhaps most common is PCIe SSDs (aka: NVMe or M.2 slots). ------ So our modern PCIe "backplane" gives us storage, extra compute (GPUs most commonly), longer-distance network access (fiber optics, ethernet, etc. etc.). What else do you want? Sound cards (especially MIDI instruments support) maybe? Dedicated video processors? A big problem with dedicated devices is that modern CPUs are so powerful... there's not much point to buying an ElGato H264 encoder anymore when you can just buy a 16-core CPU instead and do it all in software. ---- Your standard Threadripper motherboard has 4x16 PCIe slots, and I'm pretty sure 8x PCIe to each of the slots, with full support of bifurcation (splitting into smaller PCIe slots). Surely that's enough for any of your hobby projects?
- h2odragon 5y agoWhat got me off about VME when i looked at it was the immense amount of small market, single purpose hardware that had been thrown on it and was "technically" compatible. It enabled some stuff like timed traffic lights in a way similar to how Arduinos have opened up hobby level "printer-oid" mechanisms. For reasons i cant articulate well I'm itching for a bus where CPU and GPU and RAM and IO all live together in hippie harmony. The hardware's all there and dancing to some little basic machine controller CPU anyway so lets open all that up and make everything a first class citizen, hopefully on some interconnect that will last a few years and gather some interesting surplus hardware to filter out to hackers. As to modern hardware, if i had all my dreams coming true, I'd be grabbing one of the "mining" motherboards with all that I/O broken out into channels and putting SDR's on them to make pretty waterfalls of the biggest bites of the radio spectrum i could visualize.
- dragontamer 5y agoFor hobby Arduino level, the bus of note is I2C, with all sorts of devices available. Temperature sensors, accelerometers, cameras, monitor control, flash, ram and of course... other arduinos and Rasp Pis. Of course, 1Mbit is slow but the huge amount of compatibility is pretty outstanding. ---------- Today's standard I/O might be Ethernet, as far as just randomly hooking up random compute devices together. Faster than I2C, but not quite PCIe speeds. You can't deny the huge compatibility available though. ------ PCIe is for serious business high end. A few commodity parts are available but some stuff is just really expensive. It's a professional tool for high end fabrics. The best of the best remains proprietary: Infinity Fabric, UPI. I guess OpenCAPI isn't technically proprietary but few things use that... ----- I know there are a bunch of cuda-SDR projects btw. I don't know how well they work but GPUs probably are great at Fourier Transforms and other filtering tasks.
- martin8412 5y agoI2C is present in most modern computers. Look up SMBus. SPI is as well
- geerlingguy 5y agoThe tl;dr is it's a standard mini ITX-sized motherboard for the Raspberry Pi Compute Module 4. It has a Broadcom PCIe switch that it uses to power 4 mini PCIe slots, 4 M.2 E-key slots, 1 M.2 M-key slot, a x16 slot in the standard ITX location, and an edge x1 slot. It also has dual/triple-redundant 12v power supplies (barrel, aux +/- ATX, and PoE++ header, though it doesn't use a 24-pin ATX connector, so you need to power it with an adapter or via wall wart (I used a 96W barrel plug adapter). Through the course of testing this thing, I also identified a bug in the PWM fan controller circuit—and apparently it's also a small bug present on the CM4 IO Board's implementation, but typically not a fatal one.
- otachack 5y agoAlways enjoy the blog/video posts you do, Jeff. Thanks for creating this awesome, in-depth content!
- _joel 5y agoSeconded, I'm envious of your new NAS though :)
- mashc5 5y agoDo you have any more info on the PWM bug? We’re having some issues with PWM on the RPi4 and I’m wondering if it’s related…
- ChristianGeek 5y agoOnce you get to this size and price, there’s no point in using a Pi…there are much more powerful options available.
- wongarsu 5y agoI guess it makes sense as a development board: if you are building a product around a Pi Compute Module you can use this board for quick prototyping before building your own product-specific board. But any hobbyist looking at this should seriously consider the various Pi alternatives around the $200 mark first. Or just buy a used PC.
- geerlingguy 5y agoThis is spot on. I mention in the post and the video it's an expensive board, and very specialist. The target audience is basically 'person who wants ARM64 PCI Express development board', and even there, some of the PCI Express implementation on the Pi's BCM2711 is... weird. Therefore some devices have had a hard time getting drivers going on the Pi (case in point: graphics cards and Coral TPUs I've tested). I plan on testing Radxa's CM3 and Pine64's SOQuartz too. I think some people still want a cheap(ish) CM4 motherboard that just has one x16 slot, front panel headers, and maybe a 24-pin ATX power supply connector. I think that could be made for under $100 and would also solve a lot of needs for debugging purposes.
- bserge 5y ago> Or just buy a used PC. And miss out on doing my part in destroying the environment? I don't think so, bud! I buy new everything. New phone, new computer, new car, new shoes every year. You think I reside in a developed country to live like some African? Bruh. If you don't throw out your whole PC whenever it slows down due to dust accumulated on the heatsinks, you should go live in rural China. I pay lip service to the "green" shit by buying electric cars and LEDs... Ford trucks and 50W lamps, that is. I keep my windows open in winter because I have a damn efficient heat pump, too. My fridge has no doors. Don't be a Midlands faggot, live like a king.
- mikepurvis 5y ago
- rektide 5y agoAlas PCIe switches were starting to get affordable before the great chipmaker consolidation of 2015-2019 ("and seemingly overnight the cost of these switches increased three-fold"[1]). Now most every PCIe switch is >$6/lane. Even just the 12 lanes here, on an old PCIe generation, is going to be a $72 chip, perhaps more (article: PEX8619 Broadcom PCIe switch, $129, 16 lanes, $8/lane, no stock. Compare versus Microchip nee PMC-Sierra Switchtec such as PM40028B1 at $6/lane[2]). It's a cool idea. But wow, for $435, sure feels one ought consider going for an x86 pc. The form factor is cool though. It feels insane to hope for but I'm really hoping that by the time 2025 rolls around we see some modest affordable arm chips that have Thunderbolt built in. Perhaps even multiple Thunderbolt. If nothing else, there better be some decent PCIe available by then- 8x PCIe 5.0 or better. ARM needs to start doing bandwidth, some day (in places other than server class chips); it's been on USB3.0 for a long long time. Thunderbolt + PCIe would be a great boon for general usability & connectivity. Now that Intel has made it royalty free, now that USB4 already incorporates most of the hard part (packet based switching), it might finally be the time for some real PCIe on chip. [1] https://www.anandtech.com/show/15821/microchips-new-pcie-40-pcie-switches-100-lanes-174-gbps https://www.anandtech.com/show/15821/microchips-new-pcie-40-... [2] https://www.mouser.com/c/?marcom=100722352 https://www.mouser.com/c/?marcom=100722352
- MisterTea 5y ago> If nothing else, there better be some decent PCIe available by then- 8x PCIe 5.0 or better. ARM needs to start doing bandwidth, some day (in places other than server class chips); it's been on USB3.0 for a long long time. Its not up to Arm to attach PCIe lanes but the chip makers who have been competing with x86 which already offer plenty of PCIe lanes. So far, only apple has bothered to make an Arm CPU which can compete with "PC" hardware. Hopefully AMD will offer something similar. > Thunderbolt + PCIe would be a great boon for general usability & connectivity. Now that Intel has made it royalty free, now that USB4 already incorporates most of the hard part (packet based switching), it might finally be the time for some real PCIe on chip. USB4 is based on Thunderbolt 3. Given that Thunderbolt 3 is a mess, I don't have high hopes. Look at RapidIO or 1394 for examples of better thought out interconnects and protocols. PCIe cant connect CPU's together in a NUMA system whereas RapiIO can. RapidIO also uses Ethernet physical layers so there's parallel development with Ethernet. I honestly don't like USB or contraptions invented by Intel that are invariably consumer grade with various extensions to satisfy other industries, bolted on.
- deleted 5y ago[deleted]
- bloopernova 5y agoPlease forgive my lack of familiarity with PCI express hardware, but I have a question: All those PCI express devices are all sharing the single v2 lane? Is the PCI express bus a network?
- geerlingguy 5y agoIndeed, PCI Express can be thought of in many ways like Ethernet; you can have switches just like Ethernet, though in almost all cases, PCIe is a local area bus (local to one server/machine), whereas Ethernet is still the king of networks.
- NovemberWhiskey 5y agoThat's probably the way to think about it. PCIe devices communicate point-to-point over dual-simplex serial connections. If you have something like a Raspberry Pi CM4, which only has a single PCIe lane, then there's going to be a PCIe switch.
- bloopernova 5y agoInteresting, thank you!
- Teknoman117 5y agoThe other neat thing is that peer-to-peer PCIe transactions do not have to go through the root complex (the Pi in this case). Say you have a GPU and an NVMe drive or video capture card plugged into a PCIe switch, which is then plugged into the Pi. If your software supports having these devices directly communicate, they can do so as fast as their PCIe links support doing, even though there’s only the tiny link to the Pi. Peer-to-peer transfers are only limited by the smallest link on the path between two devices on the tree, rather than the smallest link in the tree. A real world example is some of the big GPU compute servers. Some of the 4U chassis can house 20 or more cards. Many of them have all of the GPUs (320 or more PCIe lanes) plugged into an array of PCIe switches which may constrain them to 16 or 32 lanes from the CPU. The GPUs can all talk to each other a full speed, but only a few can go full speed to the CPU at a time.
- zw123456 5y agoSome friends and co-workers of mine have an ongoing bet/joke... Who can find something that the Raspberry Pi can NOT do. One more thing scratched off the list!!
- sandreas 5y agoThings that are on my wishlist: - Compute-Module should have a unified interface, that is not about to change for the next 3 generations of compute modules - Someone create a "notebook" case having a board with mount for exactly this interface - Case should have a decent keyboard and display without being to big - How about having GPIO pins hidden I would love to have an "upgradable" Notebook with arm architecture...
- nine_k 5y agoIf you want a fast laptop, your two priorities are, IMHO, the thermal design and making as much room as possible for the battery. I'm afraid that RPi level of performance in a laptop is going to be underwhelming, though still interesting for many cases. If there was a widely accepted standard for laptop main boards, like there is for desktop and server boards, that would be wonderful. I don't expect it to ever happen though.
- cjbconnor 5y agoHave you seen the MNT Reform? There's a pi compute module adapter being built for it.
- sandreas 5y agoYeah, quite bulky :-) But interesting approach.
- tambourine_man 5y agoI have no experience building PCs, but during the last decade or so I've been running RPis with 6-8 disks attached. It's great software and noise wise, but the cases were made by me with MDF (and I have no idea what I'm doing), so it's not as solid as I'd like them to be. Every time I search for rackmount or 3D printed cases I'm floored by the prices, which seem completely out of proportion. Any tips on cheep/custom computer cases are highly appreciated. Thanks
- rblatz 5y agoIt’s probably easier to buy a regular case and then fit the raspberry pi into it.
- hinkley 5y agoWe should be meeting in the middle and creating SBCs whose bolt holes spacing is identical to some other device standard. For instance 2.5” HDDs, or 3.5-2.5 adapters. Then you can find trays and enclosures and caddies that can be modified slightly to purpose. Expanding holes in sheet metal is easy. Tapping holes, welding captive nuts, and bending are a lot trickier.
- Ruthalas 5y agoThis would be excellent. That's a great idea.
- sokoloff 5y agoFor something as lightly loaded as a home computer, rivnuts are pretty darn easy and cheap way to add threads to sheet metal. Brass standoffs with a nut on the back are also readily available and cheap.
- hinkley 5y agoBrass standoffs are great but they still require a tapped hole. I was thinking more of moderate scale. I’d totally rivnut one SBC if I had a friend who could show me how. But I’m not doing twenty or small batches for resale. I think there’s a fraction of people in that demographic for whom a rivnut is still fancy tech. I’ve only heard about them from watching Bad Obsession Motorsports (with Rex Hamilton as Abraham Lincoln) and rivnuts are like a running gag argument between the two hosts. Welded captive nuts always win. Every time. I just looked at a rivnut catalog, and couldn’t figure out how to find a nut that would work with standard computer case screws, or in fact what tool and nut combinations worked together. I’m not gonna sort that shit out on my own.
- marcodiego 5y agoRecent 4-cores, 2.0+ Ghz and 4GB RAM ARM SBC's are plenty powerful for most tasks a home user may need. Media consumption, browsing, light text editing, editing the weekend video and even compiling small code bases. People have been doing that in chromebooks for years. Unless you need to compile large code bases, edit serious videos, process huge amounts of data or CAD/games, a simple cheap ARM computer should be enough. Too bad the desktop was taken by a monopoly and monoculture of x86-64 with windows where you are locked if you need compatibility with some proprietary formats or tools/software.
- alias_neo 5y agoI wonder if there is a blog post in this somewhere, that I could write. I have a bunch of Pi 4s (4GB). I just put one in an Argon M.2 case and was wondering what to do with it. I have a "gut feel" for how my workstation should behave, I am a (backend) software engineer by profession, tend to work my day job on an i7 laptop (XPS 15, Ubuntu) but at home I'm on Ryzen 7 1800X (Manjaro) and Ryzen 9 3900X (Debian). Is there some useful non-benchmark type "measurements" I could take by using a Pi as a workstation for a few days, that people would be interested to read about?
- marcodiego 5y agoYou can try subjective benchmarks. These ARM SBC's are as powerful as workstations from the 90's, so try to use them with as demanding software as what was run on a workstation from the 90's. Trying to replicate this would certainly do a great blog post: https://news.ycombinator.com/item?id=27796821 https://news.ycombinator.com/item?id=27796821
- 3np 5y agoIt's comparable to a brand new Intel workstation in 2010. https://www.cpubenchmark.net/compare/Rockchip-RK3399-vs-Intel-Core2-Quad-Q9500-vs-Intel-i5-760/3987vs1047vs773 https://www.cpubenchmark.net/compare/Rockchip-RK3399-vs-Inte... For most people trying this, the SD card is the bottleneck and there are options. The mentioned Rpi2 had USB 2.0 shared with storage and network. The 4B has USB 3.0 and dedicated lanes for GBE and storage. Ryzen 3700 <> RPi 4B <> RPi 2
- ed25519FUUU 5y agoDoes this make building a large NAS with an RPI doable?
- mrtweetyhack 5y agoDamn, I needed 12
- fnord77 5y agosorry if this is obvious, but how many CM4s can you plug into this board?
- geerlingguy 5y agoOne. Don't worry though, next week I'll be covering the Turing Pi 2...
- exabrial 5y agoIs there a storage controller like a SAN that can do provisioned NVMe? Something like you insert a RPI into a backplane, and it auto-provisions some storage and makes it available to the RPI, in addition to providing power/ethernet.
- FpUser 5y agoI am curious if by the time one finishes assembling all this stuff for Pi based IoT appliance the total cost (never mind time) will exceed one of some used laptop / small factor PC which can do the same thing but faster.
- aasasd 5y agoCurious how the author has a decent site, but on Youtube he automatically switches to the trashy clickbait tricks.